1) Field of the Invention
The present invention refers to a rotor with variable hydrodynamic resistance for a stationary water bicycle and to a related bicycle.
2) Description of Related Art
Stationary water bicycles, called stationary “hydrobikes”, are known to be used for carrying out fitness activities, rehabilitation, developing and toning of muscles in the legs and in the waist, athletic training and weight loss activities.
Stationary water bicycles comprise a frame and a pair of pedals to which means are generally connected for increasing the peddling resistance and thus the intensity of the physical activity.
A different type of hydrobike comprises a bladed rotor, fixedly connected centrally to the frame and connected to the pedals. The intensity can be set by manually adjusting the opening of the blades and the related resistance according to a plurality of preset positions.
U.S. Pat. No. 5,690,588 shows, for example, a device of this type in which the flat blades can be manually oriented according to a preset number of angular positions with respect to the axle of the rotor. A button loaded by a helical spring ensures that the preset angular position is held until it is pressed to carry out a new adjustment.